It is common practice in the production of electronic assemblies to first design the assembly and then painstakingly produce a prototype, each step involving considerable time, effort, and expense. The prototype is then revised, and often times the process is repeated until the design has been optimized. After optimization, the next step is production. Since the design time and tooling costs are very high, electronic assemblies are usually practiced only in high-volume production. Alternate cost effective processes are not available for the production of low-volume parts, and these low-volume parts are usually inferior in quality to production parts.
Current technology for three-dimensional circuits requires that a three-dimensional substrate be formed first, then the conductors are formed on the substrate in a photolithography process. Three-dimensional circuits with multilayer conductors or fine lines and spaces incur a high cost. While many have endeavored to manufacture three-dimensional circuits in various ways, each requires expensive custom molds and phototools. Because of the high capital expense and the long lead times required to produce these types of circuits, they are typically limited to those situations where high volumes, long lead times, or high profit margins can justify the complexity. Hence, there continues to be a need in the design and production of three-dimensional circuits for an enhanced capability to rapidly and reliably move from the design stage to a prototype stage, and then to low cost production. Accordingly, those concerned with the production of these types of circuits have long recognized the desirability of a rapid, reliable, and economical method to fabricate complex three-dimensional circuits. The present invention fulfills these needs.